12X24 Shed/Workshop - What's the best way to insulate?

[Bob Bessette]

Hi,
I'm new to this group and love it so far. So, I recently purchased a Rinnai propane heater for my 12'X24' shed. I live in the White Mountains of NH and decided to take a shot this winter and NOT insulate. I know, foolish choice, right? I use the shed for working out and as a workshop to work wood. So, I'm not in my shed every day for a long time. I still work full-time so I don't have the time to use it during the week as a workshop but do some weightlifting in there and we oftentimes do DIY projects.

Just as a test I created kind of like a cocoon out of plastic inside the shed hoping that it would stay warm enough to lift and to work in there. Needless to say, this spring/summer I plan on insulating but I'm really not sure what method to use. I do like the idea of spray-foam insulation as it would be quick but I would imagine it would be pretty expensive. Does anyone out there have any idea how much it would cost to do a 12'X24' shed?

Am I better off just using foam board or some other material? Any stories from anyone out there who has already done this would be helpful. I don't plan, at least initially, on covering the walls with any type of paneling or plywood after insulation is in place and I really don't care how it looks inside as I just want it to be warm during the cold months and cooler in the heat of summer.

I'd love to hear from anyone out there who has tackled this project and pictures are welcome!

Best,
Bob

[Bill Dufour]

If the studs are open it is cheaper to cut foam board to fit with 1/4" gaps all around then foam the gaps to seal it in place. Fire code will require drywall over insulation unless it is rockwool. Install rough wiring or empty conduit before insulating.
Bill D.

[Damon McLaughlin]

Bob,

I have a 12x16 shed that I converted to my shop here in Eastern Washington. The first winter I did not insulate the shop, I learned my lesson. The following summer I insulted by placing 1" rigid insulation boards (the white ones with foil on one side) between the wall studs. I added rockwood batt insulation between the studs in the ceiling. The following winter my shop was so much more comfortable and with my 240v 4800 watt heater it only cost me about $50 a month to keep the shop heated 24/7.

The floor though was always cold and my feet hurt. So this year I insulated the floor by playing a layer of 1" rigid board insulation on top of the floor, then a layer of 3/4" tongue and grove sheeting and then vinyl flooring. My floor is no longer cold and according to the meter and with temperatures in the teens its costing me about $35 a month to keep my shop at 68 degrees 24/7.

I hope this helped.

[Bill Jobe]

Bob,

I have a 12x16 shed that I converted to my shop here in Eastern Washington. The first winter I did not insulate the shop, I learned my lesson. The following summer I insulted by placing 1" rigid insulation boards (the white ones with foil on one side) between the wall studs. I added rockwood batt insulation between the studs in the ceiling. The following winter my shop was so much more comfortable and with my 240v 4800 watt heater it only cost me about $50 a month to keep the shop heated 24/7.

The floor though was always cold and my feet hurt. So this year I insulated the floor by playing a layer of 1" rigid board insulation on top of the floor, then a layer of 3/4" tongue and grove sheeting and then vinyl flooring. My floor is no longer cold and according to the meter and with temperatures in the teens its costing me about $35 a month to keep my shop at 68 degrees 24/7.

I hope this helped.

It helped me. Thank you

[Bill Jobe]

I think I'm on topic with this:
I am considering r-11 foam board, then roles of sound deadening bat.
I do not yet know what the best over that would be. I read that sheet rock helps deaden sound.
I hope responces to my questions are helpful to you, too, Bob.
My apologies if it seems I stepped on your thread.

[Mike Hutchison]

My shop is a 12' x 24' metal building w/ metal roof. The P.O. insulated it w/ batt insulation
including the ceiling
I have had issues with condensation in the winter time; located in Central Florida
A year or so ago I had someone give me a quote of $500 to spray foam insulate the ceiling
Probably should have jumped on that but I started looking at what it would take to prep for
the insulation process: strip out all the existing ceiling insulation and dispose of same,
move out contents of shop (not a practical option) or covering everything with tarps
Guess I wimped out and told myself I didn't have the time for that labor
Hope this of some help in terms of cost

[Bill Dufour]

If you do fibeglass pay a little extra and get the R-15 in the walls. 15% more insulation for very little upfront cost. either dense pack or rockwool. Similar deal on foam board. The polyiso is more insulation but it costs more. How cold is it in winter?
I do not understand why R-13 is allowed to be sold. The big box stores do not stock R-15 here and many summer days are over 100 degrees. But double pane windows are required!
Consider horse stall mats for the floor. At least where free weights will be used

[Bob Bessette]

Hi Bill,
It can get to below zero on occasion for sure as I am in the White Mountains of New Hampshire. I would say on average during the day in the winter it's 20 degrees or so and down to the single digits at nights depending on the severity of the winter. I'm going to look into the R-15. I thought that at least by adding a barrier of plastic on the ceilings and sealing around the doors and one window would've helped but I'm not convinced it has at this point.

It should be fun moving out my Sears Craftsman table saw (very old and heavy), band saw, workbench, and weights but I know I have to do this for sure. I want to get a cost estimate from a local insulation guy before I decide whether or not to do this on my own.

Thanks,
Bob

[John K Jordan]

If you do fibeglass pay a little extra and get the R-15 in the walls. ...

When I built my shop I used 2x6 studs, for strength and ease of construction between 6x6 posts but also for the extra space for insulation. I used R-19 fiberglass but I see R-21 is available now. But with a very small building it would be a decision between using every available inch and keeping warmer/cooler.

[Bob Bessette]

Thanks John for your input. I appreciate it...

[Bill Dufour]

I said r15, assumed 2x4 walls. In a shop 2x6 spaced at 24" might be better for insulation and about the same wood cost. Look into heavy duty aluminum foil instead of plastic sheets.
The spray foam will provide perfect seal while shoved in foam will not seal that tight. You need a good seal at top and bottom of the wall. And around every penetration like windows and doors.
Bil lD

[Bill Dufour]

The little den/computer room addition to my house used 2x4 rafters with no insualation. I ripped the ceiling tiles glued over 1/4" plywood down and shoved in 2" polyiso foam board. leaving a air gap on top. Then I screwed on more 2" foam board at right angles to give 4" of foam insualtion. Then I used really long screws to hold up the drywall ceiling. It stays much cooler on 110 degree days.
Bil lD.

[Bob Bessette]

Hi Damon,
This is helpful. Could you possibly provide a link to Home Depot or Lowes of the exact product that you used? Is your foam board, between the studs, exposed? I was thinking I would just leave them exposed instead of investing in material to cover them. My shed is like a gambrel-type so I would have to also go all the way up the inside of the roof with the foam board as well. Just not sure how to handle the area around the ridge vent. I'll have to do some you tube-ing to see how that is handled. I'd love to see some pics and you could send directly to my email address - bbessette55@gmail.com. Thanks for your advice!

Bob,

I have a 12x16 shed that I converted to my shop here in Eastern Washington. The first winter I did not insulate the shop, I learned my lesson. The following summer I insulted by placing 1" rigid insulation boards (the white ones with foil on one side) between the wall studs. I added rockwood batt insulation between the studs in the ceiling. The following winter my shop was so much more comfortable and with my 240v 4800 watt heater it only cost me about $50 a month to keep the shop heated 24/7.

The floor though was always cold and my feet hurt. So this year I insulated the floor by playing a layer of 1" rigid board insulation on top of the floor, then a layer of 3/4" tongue and grove sheeting and then vinyl flooring. My floor is no longer cold and according to the meter and with temperatures in the teens its costing me about $35 a month to keep my shop at 68 degrees 24/7.

I hope this helped.

[Damon McLaughlin]

Hi Damon,
This is helpful. Could you possibly provide a link to Home Depot or Lowes of the exact product that you used? Is your foam board, between the studs, exposed? I was thinking I would just leave them exposed instead of investing in material to cover them. My shed is like a gambrel-type so I would have to also go all the way up the inside of the roof with the foam board as well. Just not sure how to handle the area around the ridge vent. I'll have to do some you tube-ing to see how that is handled. I'd love to see some pics and you could send directly to my email address - bbessette55@gmail.com. Thanks for your advice!

Bob,

I'm sorry I didn't see your message until just now. For the walls I used 1" foam board insulation. I had to cut it down to fit between the studs. I have the foil side facing towards the inside of the building. I did not cover up the walls. Here in eastern Washington our coldest temperatures will be as low as minus ten but our normal winter days will be in the teens. Though this board does not provide a large R value I find it very adequate.

For the ceiling I used this Rockwood insulation. I chose this because its easy to work with and doesn't itch. You'll want to wear a dust mask as its quite dusty to work with. Once in place its fine. I may one day cover up the ceiling with hardiboard.

With just the two above I kept my thermostat set at 68 (plus or minus) and it was fine. But the floor was always cold.

So this fall I insulated the floor with 1" insulation boards, the 1" version of this board. Lowe's doesn't stock the 1" but they ordered it and had it the next day. It has good R value and a high compression rating. I then used this tongue and groove subfloor right over the foam boards. I used vinyl flooring on top of that.

Whatever I set my thermostat to, say 68 degrees, the walls, floor and ceiling are all 68 degrees. My electric bill floats between $35 and $50 a month when leaving the heater on 24/7. The one thing I probably could do is use a bit of foam insulation around the two window frames.

[Bob Bessette]

Thanks Bill, I'll check on the local fire codes. All of my wiring is already in place. Interesting in that you say to cut foam board with 1/4" gaps and then foam the gaps to seal it in place. What type of foam would I use? I assume you are talking about spray foam? Why not just cut the foam board to fit snugly?

Thanks,
Bob